1. Field of the Invention
The present invention relates to a rotary disk acceleration mechanism, and in particular to a rotary disk acceleration mechanism for exercise equipment.
2. The Related Arts
Population is gradually concentrated in large cities and under such a condition that a great population resides in a limited area, it becomes very extravagant to provide a large amount of space for doing exercise. Even in a public place, doing exercise may only be achieved by spending money and time. Due to such reasons, various forms of indoor exercise equipment are available in the market and one the most commonly used is a stationary bike.
The known stationary bike has been developed for years. Instead of the simple function of being used as a substitute for exercise space, the consumers now ask for an upgraded function of adjustability of training weight for the stationary bikes.
The measure that an early stationary bike adopts to adjust the training weight is to adjust the weight of a flywheel. This is troublesome for users. A subsequent improvement in this respect is increasing the resistance of the flywheel by which the energy required to achieve the same rotational speed of the flywheel is raised, whereby a user must spends more physical strength to make the flywheel rotating at the same speed and the weight of training is thus enhanced.
In an early time, the measure of increasing resistance of flywheel was done by adjusting the spring force of a spring and the spring biased a brake shoe to abut against the flywheel. This is effective in reducing the speed of the flywheel or in other words increasing the resistance of the flywheel, but the brake shoe is gradually worn out. Further, for a long time use, the brake shoe generates high temperature and thus releases odors, as well as noises.
The most commonly used measure of adjusting flywheel resistance is to generate electromagnetic resistance induced by power generation coupled thereto. Such a structure requires mounting a power generation system to the stationary bike for the generation of electrical power.
A conventional power generation system used in the stationary bike comprises a plurality of permanent magnets mounted to an inner circumferential surface of a flywheel of the bike and a coil core that is formed by stacking a plurality of silicon steel plates set at a location corresponding to the permanent magnets and comprising a plurality of coils of wire each corresponding to the magnets with a predetermined gap present therebetween. Such a conventional structure has drawbacks including: large volume, small amount of power generated in low rotational speed, great waste of material cost, high temperature in operation, being hard to assemble, and high human labor cost.
Another known power generation system used in a stationary bike comprises a structure that include a planetary gear mounted to an inner circumferential surface of a flywheel of the stationary bike, whereby power generation can be realized through mating engagement among a plurality of gears. Such a conventional structure has disadvantages, which include: requiring a complicated gear based structure that is composed of various gears and toothed wheels, high material costs, great noise generated in the operation of the gears, being hard to assemble, high human labor cost, speed magnification being limited by the structure.
In another known power generation system used in a stationary bike, ring magnets are mounted around the shaft of a flywheel of the stationary bike and a coil core that is composed of stacked silicon steel plates is provided at a location facing the ring magnets. A plurality of wire coils is wound around the coil core with each coil facing and spaced from the magnets by a predetermined gap. Such a conventional structure is advantageous for being of a small size, but it also has disadvantages including: small amount of power generated in low rotational speed, great waste of material cost, being hard to assemble, and high human labor cost.
In another known power generation system used in a stationary bike, a power generation module is provided adjacent to a flywheel of the stationary bike. The power generation module has a rotor that is coupled by a belt to an outer circumferential surface of the flywheel of the stationary bike. When the flywheel rotates, the belt drives the power generation module to generate electrical power. Such a conventional shows certain drawbacks, including: requiring an externally mounted power generation module, being hard to assemble, high material costs, high human labor cost, and difficult maintenance.
All these various known techniques are effective in generating electricity, inducing a brake power, and achieving the purpose of doing exercise, but they are complicated structures and the sizes are generally bulky, making it impossible to effectively make use of a limited amount of space.